US3909404A - Composition and process for electrodepositing a black chromium deposit - Google Patents
Composition and process for electrodepositing a black chromium deposit Download PDFInfo
- Publication number
- US3909404A US3909404A US335602A US33560273A US3909404A US 3909404 A US3909404 A US 3909404A US 335602 A US335602 A US 335602A US 33560273 A US33560273 A US 33560273A US 3909404 A US3909404 A US 3909404A
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- US
- United States
- Prior art keywords
- amount
- chromium
- ions
- selenium
- black
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D3/00—Electroplating: Baths therefor
- C25D3/02—Electroplating: Baths therefor from solutions
- C25D3/04—Electroplating: Baths therefor from solutions of chromium
- C25D3/08—Deposition of black chromium, e.g. hexavalent chromium, CrVI
Definitions
- Black chromium is a term used to describe .the electrodeposition of chromium'which' is black -in appearance,-and which is formed during the electrodeposition of a hexavalent chromium containing solution which is substantially lacking in thepresence of sulfate Various references have described methods of-producing black chromium, such as US. Pat. Nos. 3,419,481 and 3,511,759.
- a black chromium deposit can be obtained from a chromium electroplating bath having fluoride ions and an effective blackening amount of selenium ions. It has been surprisingly found that selenium is particularly effective in giving a black chromium depoit, when the amount of selenium is' present'in an amount of at .least 0.1 grams/liter. The fact that the use of selenium will give a black deposit is particularly surprising, since tellurium, in equivalent amounts, will normally not give a black chromium deposit.
- Applicants invention is directed to a chromium electroplating solution which will result in a black chromium deposit.
- the electroplating solution can be described as having a source of chromium ions, preferably, hexavalent chromium ions.
- Chromium may be introduced into the bath as any available grade of chromic acid (Cl O3), as well as any other source of chromium ions.
- Selenium that is used in the present application should contain an effective blackening amount, preferably, at least 0.1 grams/liter of selenium ions. There is no upper limit that may be employed, other than a practical limit in that the more selenium that is employed, the more costly will be the deposition of black chromium. A practical upper limit will be approximately 10 grams/liter.
- the selenium may be introduced into the bath in any form that will dissolve in the bath and give the desired amount of selenium ions, such as selenium metal, selenium oxide, and the like.
- a source of fluoride ions should be employed in order to give good coverage to the black chromium deposit, preferably, the amount of fluoride ions that may be employed in order to give good coverage to the black chromium deposit, preferably, the amount of fluoride ions that may be employed ranges from about 0.5 grams/liter to about 2 grams/liter.
- Fluoride ions may be introduced into the bath in any form which will dissolve'in the bath and give the desired amount of fluoride ions, such as, hydrofluoric acid, fluoboric acid, fluosilicic acid and bath soluble alkali metal, alkaline'earth metal, heavy metal and ammonium salts thereof.
- sulfate ions should normally not be-present. If sulfate ions are present, then a bright chromium deposit willbe obtained,: rather than the desired black chromium deposit.
- a metal ion may be employed to decrease. the content .by precipitating the sulfate ions.
- Preferredmetal ions that may be employed 'are alkali oralkali'ne' earth metal-ions, most preferably, barium, calcium; and the like.
- the lower limit of the metal that may beemployed is about 5- grams/liter calculated as barium hydroxide.
- the upper limit would be a practical upper limit, due to costs, preferably about 100 grams/- liter (calculated'asbarium hydroxide); most preferably, the amount of metal that may be employed'is about I to 50 grams/liter'(calcul'ated as barium hydroxide).
- the metal that will be employed is bar ium material, such'as barium hydroxide.
- black chromium electrodepositing bath such as surfactants, spray suppressants, and" the like, as are normally used in the art of chromium-electroplating.
- Uniform black chromium containing deposits are readily obtained over a current density range of about 30 asfto about 1500 asf amps/sh ft).
- the temperature 'of'th'e aqueous acidic chromium electroplating solution can be 'widely'employedsuch' as'from 10C to 45C.
- a chromium electroplating solution containing 100-400 grams/liter of chromium trioxide was prepared having the following amount of additional materials: Cr O 7 Grams/liter; sodium hydroxide 57.5 grams/liter; K Si F 1.0 2.0 grams/liter; and selenium ions 100200 grams/liter.
- the chromium electroplating solution was used in the Hull cell and chromium was electrodeposited at a temperature of 60F. An uniform, black chromium deposit was obtained over 50 to milliliters of the Hull cell panel.
- EXAMPLE II In order to improve the stability of the electroplating solution, the following formulation was prepared. A Hull cell panel was prepared by electrodepositing bright nickel on to steel. The following formulation was substantially more improved, than the formulation of Example I.
- the electroplating solution contained: 400 grams/liter of CrO 2O grams/liter of barium hydroxide, 2.0 grams/liter of K Si F and 2 grams/liter of SeO. A uniform chromium deposit was obtained in the cell panel.
- the direct current is periodically interrupted during the electrodeposition of black chromium, a more uniform black deposit can be obtained over a wider current density range employing this technique.
- This can be best described as follows; in a 30 second period, the current is on (electrodeposition occurs) for more time than it is off. Preferably, the current is on 75% of the time and off 25% of the time in a 30 second period. The most preferred cycle is that of 7 seconds on and 2 seconds off.
- EXAMPLE IV When utilizing the procedure of Example I in a Hull cell panel, and containing: 1.0 grams/liter of selenium dioxide, with a temperature of 110F., minutes of depositing chromium in a Hull cell at 5 amps, a uniform black deposit was obtained over 50 millimeters of the panel. Employing a current interruption of 7 seconds on and 2 seconds off, during 5 minutes, to a similar panel, an excellent uniform black deposit was obtained over milliliters of the panel. Clearly, the use of current interruption gave a broader deposition of black chromium.
- An aqueous acidic black chromium electroplating solution having fluoride ions in an amount of about 0.5 to about 2 g/l, comprising a about 100-400 g/] CrO in the absence of sulfate ions, and an effective blackening amount of selenium in the amount of at least about 0.1 g/l.
- a process of electrodepositing black chromium from an acidic chromium bath comprising passing a current from an anode to a cathode through the solution of claim 1 to form a uniform black chromium deposit.
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Electroplating And Plating Baths Therefor (AREA)
Abstract
Description
Claims (7)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US335602A US3909404A (en) | 1973-02-26 | 1973-02-26 | Composition and process for electrodepositing a black chromium deposit |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US335602A US3909404A (en) | 1973-02-26 | 1973-02-26 | Composition and process for electrodepositing a black chromium deposit |
Publications (1)
Publication Number | Publication Date |
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US3909404A true US3909404A (en) | 1975-09-30 |
Family
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Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US335602A Expired - Lifetime US3909404A (en) | 1973-02-26 | 1973-02-26 | Composition and process for electrodepositing a black chromium deposit |
Country Status (1)
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US (1) | US3909404A (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4174265A (en) * | 1975-11-11 | 1979-11-13 | Tomoya Minegishi | Black chromium electroplating process |
JPS5589495A (en) * | 1978-12-27 | 1980-07-07 | Shizuokaken | Black color electric chrome-plating liquor |
US5019223A (en) * | 1988-01-05 | 1991-05-28 | The Council Of Scientific & Industrial Research | Black chromium plating bath useful for solar reflecting coatings |
EP3162919A1 (en) * | 2015-10-29 | 2017-05-03 | GmbH Franz | Method for efficient black chromium plating i |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2826538A (en) * | 1955-05-03 | 1958-03-11 | Columbia Broadcasting Syst Inc | Metal blackening process |
US2985567A (en) * | 1959-03-16 | 1961-05-23 | Allied Chem | Electrodeposition of black chromium coatings |
US3340165A (en) * | 1964-07-20 | 1967-09-05 | M & T Chemicals Inc | Method of electroplating microcrack chromium |
US3511759A (en) * | 1966-04-08 | 1970-05-12 | Diamond Shamrock Corp | Method and electrolytes for electro-depositing black chromium |
US3514380A (en) * | 1967-02-17 | 1970-05-26 | Kewanee Oil Co | Chromium plating from a fluosilicate type bath containing sodium,ammonium and/or magnesium ions |
US3661733A (en) * | 1966-01-18 | 1972-05-09 | Wilhehm Roggendorf | Chromium electroplating |
US3723261A (en) * | 1970-10-30 | 1973-03-27 | Allied Chem | Black chromium plating process and composition |
-
1973
- 1973-02-26 US US335602A patent/US3909404A/en not_active Expired - Lifetime
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2826538A (en) * | 1955-05-03 | 1958-03-11 | Columbia Broadcasting Syst Inc | Metal blackening process |
US2985567A (en) * | 1959-03-16 | 1961-05-23 | Allied Chem | Electrodeposition of black chromium coatings |
US3340165A (en) * | 1964-07-20 | 1967-09-05 | M & T Chemicals Inc | Method of electroplating microcrack chromium |
US3661733A (en) * | 1966-01-18 | 1972-05-09 | Wilhehm Roggendorf | Chromium electroplating |
US3511759A (en) * | 1966-04-08 | 1970-05-12 | Diamond Shamrock Corp | Method and electrolytes for electro-depositing black chromium |
US3514380A (en) * | 1967-02-17 | 1970-05-26 | Kewanee Oil Co | Chromium plating from a fluosilicate type bath containing sodium,ammonium and/or magnesium ions |
US3723261A (en) * | 1970-10-30 | 1973-03-27 | Allied Chem | Black chromium plating process and composition |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4174265A (en) * | 1975-11-11 | 1979-11-13 | Tomoya Minegishi | Black chromium electroplating process |
JPS5589495A (en) * | 1978-12-27 | 1980-07-07 | Shizuokaken | Black color electric chrome-plating liquor |
JPS5627599B2 (en) * | 1978-12-27 | 1981-06-25 | ||
US5019223A (en) * | 1988-01-05 | 1991-05-28 | The Council Of Scientific & Industrial Research | Black chromium plating bath useful for solar reflecting coatings |
EP3162919A1 (en) * | 2015-10-29 | 2017-05-03 | GmbH Franz | Method for efficient black chromium plating i |
WO2017071817A1 (en) * | 2015-10-29 | 2017-05-04 | Franz GmbH | Method for efficient black chroming i |
EP3312307A1 (en) * | 2015-10-29 | 2018-04-25 | Franz GmbH | Method for efficient black chromium plating i |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: OXY METAL INDUSTRIES CORPORATION Free format text: CHANGE OF NAME;ASSIGNOR:OXY METAL FINISHING CORPORATION;REEL/FRAME:003967/0084 Effective date: 19741220 |
|
AS | Assignment |
Owner name: HOOKER CHEMICALS & PLASTICS CORP. Free format text: MERGER;ASSIGNOR:OXY METAL INDUSTRIES CORPORATION;REEL/FRAME:004075/0885 Effective date: 19801222 |
|
AS | Assignment |
Owner name: OCCIDENTAL CHEMICAL CORPORATION Free format text: CHANGE OF NAME;ASSIGNOR:HOOKER CHEMICAS & PLASTICS CORP.;REEL/FRAME:004126/0054 Effective date: 19820330 |
|
AS | Assignment |
Owner name: OMI INTERNATIONAL CORPORATION, 21441 HOOVER ROAD, Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:OCCIDENTAL CHEMICAL CORPORATION;REEL/FRAME:004190/0827 Effective date: 19830915 |
|
AS | Assignment |
Owner name: MANUFACTURERS HANOVER TRUST COMPANY, A CORP OF NY Free format text: SECURITY INTEREST;ASSIGNOR:INTERNATIONAL CORPORATION, A CORP OF DE;REEL/FRAME:004201/0733 Effective date: 19830930 |